Tony Iommi, the guitarist for Black Sabbath, is getting adult stem cell treatment for cartilage damage. More than 40 years of guitar riffs have taken their toll.

I’ve had this problem with my hand and I’ve had this stem-cell treatment on it. The cartilage (was worn out between) the joints, and the joints (were) rubbing on the joints. It was bone to bone and it was getting a bit painful.”

Professor Peter Buckle of the Robens Centre for Health Ergonomics at the University of Surrey notes that strain injuries are common for rockers. “Guitarists need to pace themselves more,” he said. The adult stem cell treatment apparently works by restoring defective muscles and helping to regenerate cartilage growth. Given the success of adult stem cells, worried fans shouldn’t be paranoid.